Metal-lined brick



Filed April 2, 1951 United States Patent METAL-LINED BRICK Jean dAmbly,Lorette, France, assignor to Compagnie des Forges et Acieries de laMarine et de Saint-Etienne, Samt-Chamond, France, a corporation ofFrance Application April 2, 1951, Serial No. 218,779 Claims priority,application France April 7, 1950 1 Claim. (Cl. 7235) This inventionrelates to basic bricks for the construction of metallurgical furnaces,of the type that are lined with or encased in an oxidizable metal-platecasing at least throughout a major portion of their surface.

Many types of structural elements for furnaces are known in which therefractory material is retained within a casing made of ordinary steelplate which will become oxidized to a greater or smaller depth in theareas thereof adjacent to the hot furnace walls. The purpose of suchoxidizable linings or casings is two-fold: first, the increase in volumeresulting from the oxidization of the metal on the hotter side of theelement ensures the formation of a tighter seal at the joints betweenadjacent bricks towards the furnace chamber; and second, the nonoxidized sheet plate on the cooler side provides a mechanicalreinforcement for the furnace walls.

It is an object of this invention to provide a metal-lined brick encasedon three or four of its sides by a process involving a directcompression of the refractory material into a U-shaped sheet-metalcasing or channel liner possessing high mechanical strength in all itsparts.

Another object is to provide a basic brick encased in a channel-shapedsheet metal casing wherein the refractory material is compresseddirectly within the casing in a direction normal to the base or web ofthe channel without producing any distortion or buckling in the flangesof the channel casing.

A further object is to provide a sheet-metal casing for the productionof metal-lined basic bricks which is adapted to be inserted downwardlyin inverted condition into a moulding cavity after refractory materialhas already been charged into said cavity, the flanges of the casingbeing so formed at their edges as to prevent any buckling or distortionof said flanges during the brick-manufacturing steps.

A further object of the invention is to provide a basic brick of thetype intended to be suspended in the erected structure from a hanger,provided with a sheet metal casing lining three sides and one end faceof the brick, and wherein the refractory material above the suspensionmeans or hanger is retained by that part of the casing which lines thesaid one end face of the brick.

In the U. S. patent specification 1,106,725, a method of kilnconstruction was described using structural elements comprising acontainer of arbitrary shape filled with a core of basic material, thesaid elements being juxtaposed and retained in assembly by means of asuitable binder. The preferred embodiment of the structural elementdescribed in the said patent is of cylindrical form, so that theoxidizable casing only exerts a comparatively small effect in sealingthe inter-brick joints, the efiicacy of such seal being primarilydependent on the more or less satisfactory way in which the bindermaterial clings to the adjacent elements.

Inasmuch as the bricks in a wall or vault are juxtaposed, it is notnecessary that all the sides of each brick be metal-lined for thepurpose of providing each interbrick joint with an oxidized metal seal.In actual practice, the end faces at the internal and external sides areleft unlined, while three of four of the remaining (side) faces aremetal-lined.

A brick encased in a U-shaped sheet metal casing was described in U. S.patent specification 1,672,524. This brick unit consists of a casing andan agglomerated body of refractory material separately formed andsubsequently interfitted with each othc A result of this construction isthat relative slippage between the two constituent elements ofthe brickunit always remains possible and in such case the clearance which arisesbetween the elements impairs the efiiciency of the joint, since theexpansion resulting from oxidization of the steel liner may not besuflicient to compensate'for such clearance and seal the joint.

To improve the adhesion between the refractory filling and the steelcasing or liner, in the case of bricks preencased over three usefulfaces thereof, the simplest method would apparently consist of providinga channel-shaped casing by any conventional cutting and pressingmethods, placing this channel into 'the mould of the agglomerating pressand then filling it with the refractory brick material, and finallycompressing said material directly 'within the casing. However, whenthis procedure is applied to a casing produced from a sheet elementsimply formed 7 to channel section so as to provide a casing havingdimensions corresponding with the external dimensions of the brick, itis found that upon compression of the brick material in the casingretained in the press mould or die, the flanges of the channel casingwill tend .to buckle or distort to such anextent that the bricks thusproduced have to be scrapped. I

To overcome this difficulty, various means have been conceived, such asreducing thetlength of the channel flanges. When this is done howevertwo of the three lined sides of the resulting bricks are notmetal-linedthroughout their full height. Such bricks will therefore present areaspossessing lesser resistance to mechanical impacts and to disaggregationcaused by temperature variations, .and the masonry joints in such areasare less tightly sealed because of the absence of the oxidizable metal.It has alsobeen suggested to use pairs of oppositely-arranged channelsections for lining the bricks, but this method of brick construction isexpensive, timeconsuming and difficult to carry into practice.

In U. S. patent specifications 2,247,376 and 2,289,911, it has beensuggested with the object of preventing distortion of the casing duringthe moulding process, to weaken the base orweb of the channel along alongitudinal line by the provision of slots along this line over agreater part of the length of the Web. This of course weakens thestructural strength of the resulting brick and moreover requires theexertion of great care in handling the casings if distortion along theweakened line is-to be avoided.

I have now found that it is possible to prevent distortion or bucklingof the flanges of a channel-casing for a brick unit of the typedescribed provided with a lining over three or four of its sides, whileat the same time using a casing in which the flanges extendsubstantially throughout the full extent of the related brick surfaces,provided the free ends of the casing flanges are conformed to a suitableconfiguration hereinafter specified, rather than being flat.

Thus the invention provides a method of producing composite bricks fullylined over three (or four) of their faces, which comprises providing ametal casing having an equal number of sides to the number ofsides ofthe brick which are to be lined and corresponding in dimensions to theouter dimensions of the brick, the said casing including a base web andperpendicularly up standing flanges along-the side edges of the brick,the free end of each flange terminating in a cylindrical surface havingits convexity directed towards the inside of the casing, placing saidcasing into a mould cavity, in such a way that the flanges respectivelybear along at least one generatrix thereof against a corresponding sidewall of said cavity, and" directly compressing the brick material insaid casing.

The cylindrical section terminating each flange may be formed by bendingthe appropriate edge of each flange, or in any other suitable manner, e.g. by grinding.

One important effect of the provision of such a cylindrical'surface isthat it presents an'incline or taper to the material to be bricked ofsuch configuration that the material will not tend to be retained on theterminal edges of the casing flanges and will be directed or guidedtowards the-inside of the casing. The radius of curvature of across-section of this surface may be provided as small as will beconsistent with the friction coeflicient of the sheet metal, which inturn depends on the nature of said metal and the surface conditionthereof. The subtended angle of the cylindrical cross-section assumed tobe circular will also depend on the same factors.

The invention further comprises a sheet metal brick casing forpracticing the method above defined, as well as the resulting linedbricks produced by such method.

Claws punched out of the casing inwardly thereof may be provided inconventional manner to bond the metal lining to the brick material. Acover plate may be secured in a similar way and at the same time overthe fourth side of the brick.

The invention will be clearly understood from the ensuing description ofsome exemplary embodiments of the invention illustrated in theaccompanying drawings, wherein:

Fig. l is an isometric view of a finished brick according to theinvention;

Fig. 2 is a similar view ofthe channel shaped casing or liner used inthe construction of the brick shown in ig. V

Fig. 3 is a diagrammatical vertical section of a mould having a casingas in Fig. 2 placed in it with the flange ends thereof bent to providethe cylindrical surface according to a feature of the invention;

Fig. 4 is a similar View similar to Fig. 3 but showing a liner ofsomewhat difierent shape;

Fig. 5 is a diagrammatical vertical section of a mould having a sheetsteel liner inserted-into it prior the mouldmeans. In either case, thecasing may be so placed that its web 13 is directed upwards (Figs. 3 and4) or downwards (Fig. 5) or indeed at any desired angle. Yet a furtherprocedure would be to combine the displacements of both the casing andbrick material, said casing and material being moved towards each other.In all cases the cylindrical surfaces 12a terminating the flanges of thecasing are made to bear against the walls 16 of the moulding cavityalong a generatrix 15 of each,

cylindrical surface.

in practice, in order to impart to the resulting bricks as accurate abox-like shape as possible, it is desirable, in the event thecylindrical surfaces 12:: are formed by bending the free edges of theflanges, to keep the extent of said cylindrical surface as small aspossible, and accordingly use the smallest radius of curvatureconsistent with the thickness of the sheet metal used.

It may be stated by way of indication that good results have beenobtained with a metal sheet 1 mm. thick formed to radii of curvature of1 mm. and 2 mm. respectively for both sides, the subtendedangle of thecylindrical cross-section being about 60. In this case, the sheet metalwas cut at right angles prior to the cambering of its edges, so that theexternal arrises of the lips formed abutted against the oppositeparallel sides 16 of the moulding cavity along two generatrices 15 ofthe outer cylindrical surface, the end surface of each flange beingdirected along a diammetric plane of the cylinder.

If desired, and especially in order to make the casing edges less sharp,any other equivalent form may be imparted to such edges, and things soarranged for example that the end of flange 3.2 will bear against themould cavity wall over the whole area of the end surface 18-19 of thesheet, as in Fig. 4, rather than by only one edge or arris 15 thereof asin Fig. 3. v

To improve the bond between the brick material and its casing, claws 22are preferably punched inwards from the flanges to be embedded in thebody of the brick on moulding.

ing, the flange edges of the liner being ground along the inner arrisesthereof to provide the said cylindrical surfaces;

Fig. 6 shows one advantageous arrangement of brick according to theinvention in the construction of a wall, wherein the bricks are providedwith a sheet metal liner anchored upon the fourth side thereof; and

Fig. 7 is an isometric view of a brick lined on four sides and one endthereof adapted to be suspended from a T- shaped hanger tenon.

In a simple embodiment of the invention illustrated in Figs. 1 and 2,the brick 10 according to the invention is lined throughout the fullextent of three of its four sides with a metal liner or casing 11. Thiscasing consists of a channel including two flanges 12 upstandingperpendicularly from the web 13 of the channel. The casing correspondsin its dimensions with theexternal dimensions of the brick to beproduced, allowance being made for the necessary clearance required forits insertion into the mould. As is clearly shown in the drawings, theedges of the casing flanges 12 remote from the web are slightly bentoutwards to provide outward cylindrical surfaces 12a having small radiiof curvature.

The casing 11 may be placed in the moulding cavity before or after thebrick material has been charged into it, as desired, and the materialthen compressed in the casing by any appropriate means; oralternatively, the material may be tamped into the cavity during thecompression step by means of a piston 14 and suitable guide:

Fig. 5 illustrates another form of embodiment of a casing according tothe invention arranged in a moulding cavity prior to being charged withbrick material. As shown in this figure, the cylindrical surface 12:: isprovided by removing metal adjacent to the inner arris of the flange 12,for example by grinding, so that the cylindrical surface is intersectedby the outer surface of flange 12 along a generatrix 15.

Where the bricks are of the type shown in Fig. 1, and more especially inthe case of bricks provided with a cover plate anchored to their fourthside, it becomes desirable, owing to the flare provided along thearrises 12a which slightly increases the width of one side of the brickto set the bricks in alternating relationship when erecting a wall withone brick with the liner web downwards and the next with the Web upwards(see Fig. 6) so that the lateral projections will interfit with thefillets provided'a; the junction of the casing web with the casingflanges.

Steel-lined bricks of the kind contemplated herein arc frequently usedin suspended vaults and in such cases special precautions have to betaken in order to provide for the engagement of the hanger means.

In U. S. Patents 2,125,193, 2,247,376 and 2,289,9ll. steelcased bricksare disclosed wherein one side of the casing or the cover which in manycases is adapted to the fourth side of the brick, is widely cut out toclear the recess into which the hanger engages and allows its beinginserted into said recess, with the end of the encased brick still beingfree from a metal lining.

Obviously the method described makes it possible to construct a bricklined over three sides and one end thereof, with the use of a casingconsisting of a web and three flanges upstanding therefrom. Such anarrangement is especially desirable where the brick is to be suspendedor hooked. Fig. 7 shows such a brick which is designed for being,suspendedfrom a T-shaped hanger or hook. In this case, the casing wouldcomprise, in addition to the web 13 and the side flanges 12, a thirdflange 23 also formed with a cylindrical surface 23a along its freeedge. A cutout 24 is formed in the flange 23 for insertion of the hangershank, and a T-shaped cutout 25 is formed in the web 13, both cutouts 24and 25 being formed in corresponding positions, for example by means ofa common punch in a single punching step prior to bending the flange 24along the edge 26. Two claws 22a are preferably punched inwards from theflange 23 in a manner similar to the claws 22 of flanges 12. Inasmuch asthe suspension of a brick of this kind is assured only by the odd squareinch or so of brick material engaging the cross-arm of the T-hanger, ametal lining over the end of the brick on the suspended side thereofwill provide a considerable reinforcement, and will make it possiblemoreover to form the notch or cutout at a point closer to the end of thebrick, whereby the brick is utilized more fully and will have a longerservice life.

It will be understood that many alterations may be made in the detailsof the brick and channel casing or liner described and illustratedwithout exceeding the scope of invention as defined by the ensuingclaim.

What I claim is:

A metal lined refractory brick for metallurgical purposes comprising anouter oxidizable elongated channel,

shaped sheet steel casing including a web, at least two upstanding flatflange portions extending at right angles from the web along the twolonger edges thereof, refractory brick material compressed in the casingand having an outer elongated exposed face extending between the flangeportions, said web and flange portions completely covering therespective sides of the brick material, said flange portions having aheight just equal to the height of the brick material, each of saidflange portions terminating in an outwardly turned free edge portion,said free edge portion of each flange portion extending over an angle ofnot more than and extending parallel with its respective longer edge ofthe web and forming a cylindrical surface whose convexity is directedtowards the brick material, the free edge portions being flush with theelongated exposed face of the brick material.

References Cited in the file of this patent UNITED STATES PATENTS296,825 Du Puy Apr. 15, 1884 1,562,519 Ruppel Nov. 24, 1925 1,628,318Hosbein et a1 May 10, 1927 1,922,774 Maul et al Aug. 15, 1933 2,016,860Hasche Oct. 8, 1935 2,018,192 Sexton Oct. 22, 1935 2,073,735 Duffy Mar.16, 1937 2,152,738 Jeffery Apr. 4, 1939 2,163,435 Pollen June 20, 19392,200,270 Flores May 14, 1940 2,216,813 Goldschrnidt Oct. 8, 19402,247,376 Heuer July 1, 1941 2,288,559 Ward June 30, 1942 2,289,911Heuer July 14, 1942

